With so many moving parts during the N.F.L. free-agency period, it can be difficult to keep up with all the player changes. As the dust settles, these teams will find themselves the most changed, for better or worse.

SAN FRANCISCO 49ERS It has been quite an off-season for the 49ers. A preseason pick last year to go deep into the playoffs, San Francisco imploded on the field. Then the wheels came off. Coach Jim Harbaugh, who seemed on the verge of creating a new 49ers dynasty, is gone, and the team will have to replace both the retired Patrick Willis, the heart and soul of the defense, and Frank Gore, one of the most successful running backs in franchise history, who signed with the Indianapolis Colts. Mike Iupati, a steamrollering left guard, signed with Arizona, and Justin Smith, a defensive lineman named an All-Pro at two positions in the same season, may retire. The team has made some positive moves in free agency, signing Torrey Smith and Darnell Dockett, but with so much of the veteran leadership departing and others probably on the way out as well, it is hard to believe that the 49ers will present much of a threat to Seattle and Arizona in the N.F.C. West.

Verdict: Worse. And confusing.

JACKSONVILLE JAGUARS As the 49ers said goodbye to much of their identity, the Jaguars stockpiled useful football players, a rare commodity in Jacksonville in the last few seasons. Julius Thomas, a dominant tight end, will have a chance to prove he was not a creation of Peyton Manning’s as he becomes the primary target of the Jacksonville offense. The defense was bolstered by the signings of Jared Odrick, Sergio Brown and Davon House. While none of those three are game-changing talents, they provide depth and talent on a team that previously had little of either. Unfortunately, the team lost Will Blackmon and J. T. Thomas to free agency, but the new players should represent an upgrade.

INDIANAPOLIS COLTS Humiliated by the New England Patriots in the A.F.C. championship game, the Colts are making moves that could give them control of the conference. Considering the age of their acquisitions, though, the team should not expect to have a long period of success. Frank Gore was on the verge of signing with Philadelphia, but instead he will be the first quality running back to work with Andrew Luck. Wide receiver Andre Johnson — a former Houston Texan and, like Gore, a former Miami Hurricane — also signed with Indianapolis. If he can remain healthy, Johnson will be an upgrade over the departed Reggie Wayne. On defense, the Colts added linebacker Trent Cole, who should improve the team’s pass rush. All three are senior citizens by N.F.L. standards, but with the Colts having gotten so close with inferior talent around Luck last season, the veterans could push the team over the top.

Verdict: Better. For now.

JETS Darrelle Revis is said to be guaranteed so much money in his deal with the Jets that he could afford gold Apple Watches for both wrists and still buy a private island or two in honor of his Revis Island nickname. Although many still have sticker shock, the Jets filled a major need at cornerback by signing the best one in the game not named Richard Sherman. Two years after trading Revis to Tampa Bay for a package of picks that landed the Jets Sheldon Richardson, the team now has both players and cap room to spare. The person who should be happiest, though, is Buster Skrine, a cornerback the Jets also signed, because defensive backs who play on the same team as Revis tend to suddenly look far better. Just ask Brandon Browner, who, a year removed from a suspension that cost him a trip to the Super Bowl, is now entertaining free-agent offers based on his comeback season for New England, where he manned the side of the field opposite Revis. On offense, Ryan Fitzpatrick will be a solid backup quarterback, and Brandon Marshall represents a mild upgrade over Percy Harvin at wide receiver. Both are flawed, but Marshall has had far more consistent production over the course of his career.

Verdict: Better. But at a hefty price.

PHILADELPHIA EAGLES It is easy to get the sense that Coach Chip Kelly is far from done wheeling and dealing as he reshapes the franchise, and his moves thus far have certainly been bold. Linebacker Kiko Alonso may not be as famous as the player he was traded for — running back LeSean McCoy — but he and Byron Maxwell should be huge additions to a defensive unit that was ranked 31st against the pass last season. Losing a player as talented as McCoy hurts, but Philadelphia signed Ryan Mathews, and if the team is able to sign DeMarco Murray away from Dallas, it should have little to no drop-off. Trading for Sam Bradford seems curious at best, but he may just be a place-holder at quarterback until Kelly can find a franchise signal-caller through the draft.

Verdict: Better at defense, unknown on offense.

A version of this article appears in print on , on Page B15 of the New York edition with the headline: The Free Agency Shake-Up, for Better or Worse. Order Reprints | Today’s Paper | Subscribe